The National Cancer Institute places tobacco control research in developing countries among its top tobacco research priorities in its 2006 Bypass Budget Report, reflecting concerns about the growing global disease burden attributable to tobacco. India provides an important case example of tobacco control efforts within a developing country, as the second largest country in the world with a population of over one billion people, and with an estimated 250 million tobacco users age 10 and above. This study proposes to test a comprehensive tobacco control intervention for teachers in the Indian state of Bihar, representing one of the highest tobacco-using regions in India. Teachers are an important vanguard population for tobacco control efforts in their roles as key opinion leaders in relation to community norms and role models for students. According to the Global School Personnel Survey, 78% of teachers in Bihar used some form of tobacco in the year 2000. The specific aims of this study are to: (1) assess the extent to which a comprehensive tobacco control intervention results in increased cessation of tobacco use among teachers in Bihar schools; (2) assess the extent to which a comprehensive tobacco control intervention results in changes in school tobacco control policies; (3) assess the extent to which a comprehensive tobacco control intervention results in changes in defined mediating mechanisms among teachers; and (4) assess key indicators of intervention implementation among schools assigned to the intervention condition, including the extent of the implementation of the intervention, the reach of the intervention, and the fidelity to the intervention protocol. This randomized controlled trial uses the school as the unit of intervention and randomization. Government schools (N=100) including grades 8-10 (i.e., ages 13-15) in the state of Bihar, India, will be randomly selected, recruited to participate in the study, and randomly assigned within strata (rural, urban) to one of two conditions (intervention versus delayed intervention control). Data will be collected by a teacher survey at three time points; a policy assessment; and a process evaluation. Our preliminary work in Bihar provides a critical starting point for this work, and demonstrates the feasibility of the proposed study. The intervention has been designed to balance potential intervention impact on teachers' tobacco use patterns with feasibility within the constraints of local resources, thereby maximizing the potential for dissemination.